In some devices for developing products, a cable is used as electric wiring. Wire harness is obtained by processing an electric wire or a cable and is an indispensable component in most of device provided with a plurality of units, a vehicle and the like. Therefore, recently software for supporting route design for arranging a cable (hereinafter called “route design support software”) has been sold. Since in manufacturing business, computer-aided design (CAD) is widely introduced, such support software usually designs the route of a cable arranged in a device, in a virtual space, using the design data of the device. A design support system for supporting the route of a cable can be realized by a data processing device (computer) executing the route design support software.
A cable has a fairly high flexibility. However, if the design is promoted without taking into a cable, sometimes the design of a product has to be modified due to the cable. This is because inconveniences that a cable has to be forcibly curved, its fixing workability is bad, it interferes with other components and so on are easy to be missed. In a route design using design data, such inconveniences can be easily avoided.
A route is designed by designating (generating) passing points being positions through which a cable should pass, using the design support system. In the position designation of the passing point, a positional reference being a position which is a base in specifying the position is usually selected as an attribute. For such a positional reference, one based on the origin of the coordinate system of a virtual space (hereinafter called “reference coordinates”), one based on another passing point (hereinafter called “relative coordinates”) and one based on a component (model) disposed in a virtual space (hereinafter called “model reference”) are used. Since those positional references are referenced in order to specify a passing point, it is hereinafter called “reference destination”. The above-described coordinate systems are determined by the target range of the route design and the entire device is usually managed by another coordinate system (hereinafter called “absolute coordinate system”).
The route of a cable is determined by calculating a curve passing through passing points. As such a curve, a parametric curve, more particularly a Bezier curve is generally calculated. Therefore, in each passing point, besides the position, the passing direction of a cable is usually managed as passing point information.
In a conventional design support system, the passing direction in a passing point is automatically set on the basis of the positions of passing points before and after the passing point. Therefore, in the passing point of a model reference, sometimes a passing direction toward the inside of a component (model) is set on the basis of the positions passing points before and after it (FIG. 5A).
When a passing direction toward the inside of a component is set, a route determined by a Bezier curve is not actual one since it passes through the inside of the component (FIG. 5B). Therefore, in order to surely determine an appropriate route, it is considered necessary to set a passing direction (passing point information) taking other than other passing points into consideration.
The cable itself is a deformable linear structure. Such a device is not only a linear structure with many fairly thin objects, such as an electric wire, a cable (including wire harness, an optical cable, etc.) or a wire but also a cylindrical linear structure with many fairly thick objects are sometimes attached.
Such a linear structure is sometimes inserted not only between units mounted in one device (product), such as an electrical appliance, a vehicle or the like, but also between a plurality of devices disposed in respective different places. Therefore, a route is sometimes designed in order to insert a linear structure between separate devices. Specifically, the target of route design is not only one device, but also is a plurality of devices disposed in respective different places. Therefore, it is important to easily and appropriately design a route regardless of such a difference in a target.
Patent document 1: Japanese Patent Laid-open Publication No. 2006-209362
Patent document 2: Japanese Patent Laid-open Publication No. H10-21269